Don't think it's the tuning - trying to find the culprit
Oct 11, 2006, 06:05 PM
#31
You had severe counts way before WOT which tells me at leaste fuel supply was not an issue. A good thing
Check the clearance between downpipe and member bar and if clearance is less than 1/2 inch tthen possibl=y the cause
Check the clearance between downpipe and member bar and if clearance is less than 1/2 inch tthen possibl=y the cause
Last edited by C6C6CH3vo; Oct 11, 2006 at 06:15 PM.
Oct 12, 2006, 06:31 AM
#34
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Originally Posted by C6C6CH3vo
Yeah but he was getting like 23 counts with 33% TPS value which tells me unlikely related to fuel and knock, sensor is picking up noise some kind of noise
I'm also going to check for any loose bolts on my exhaust/DP.
Would you guys happen to know of any writeups or have an idea how to go about changing the knock sensor?
I've been researching and haven't found anything.
I'm determined to find what's causing this. Although it's most likely mechanical - it's still causing timing to be pulled.
Thanks for the help.
Oct 12, 2006, 04:54 PM
#35
Knock sensor circuit integrety is checked by ECU every time ignition is turned on, if bad, SES fault will record, even if it goes bad intermittently.
Maybe theres a possibility a contacts loose disrupting the signal not enough to fault, but just enough to create static noise coincidentally the same as 20 some odd counts, as in your case.
If it was me I would backprobe the wiring for sensor resistance at respective ECU pins while shaking down everything on the isolated circuit, a faulty wire will change your reading. You got to know what your doing here though (unlike me), you can easily fry your ECU or damage it's connectors.
Somethings got to be wrong - your geting 20+ counts for no reason at all, make sure it's not noise first
Maybe theres a possibility a contacts loose disrupting the signal not enough to fault, but just enough to create static noise coincidentally the same as 20 some odd counts, as in your case.
If it was me I would backprobe the wiring for sensor resistance at respective ECU pins while shaking down everything on the isolated circuit, a faulty wire will change your reading. You got to know what your doing here though (unlike me), you can easily fry your ECU or damage it's connectors.
Somethings got to be wrong - your geting 20+ counts for no reason at all, make sure it's not noise first
Oct 12, 2006, 05:43 PM
#36
33% throttle is just about the transition point from open loop to closed loop at RPM's below 5000 (approx)
Its entirely possible there's a large fueling jump between closed loop feedback and open loop fuel maps.. That can be enough to cause knock under certain circumstances, especially if the transition is pretty lean..
Its entirely possible there's a large fueling jump between closed loop feedback and open loop fuel maps.. That can be enough to cause knock under certain circumstances, especially if the transition is pretty lean..
Oct 12, 2006, 08:50 PM
#37
Originally Posted by MalibuJack
33% throttle is just about the transition point from open loop to closed loop at RPM's below 5000 (approx)
Its entirely possible there's a large fueling jump between closed loop feedback and open loop fuel maps.. That can be enough to cause knock under certain circumstances, especially if the transition is pretty lean..
Its entirely possible there's a large fueling jump between closed loop feedback and open loop fuel maps.. That can be enough to cause knock under certain circumstances, especially if the transition is pretty lean..
Oct 13, 2006, 05:10 AM
#38
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I did another set of runs/tests, but this time with boost cranked all the way down.
This time boost was set to spike @ 15psi.
I'm still getting off boost knock. Always starting @ almost the same rpm and tps.
I'm wondering if at the time something starts rattling because of the load and vibration...
This time boost was set to spike @ 15psi.
I'm still getting off boost knock. Always starting @ almost the same rpm and tps.
I'm wondering if at the time something starts rattling because of the load and vibration...
Oct 13, 2006, 06:55 AM
#39
well, I do get knock from my downpipe hitting the crossmember, but its never really high counts.. I would seriously look at your low load transitions from closed to open loop, you keep mentioning 30% throttle or so, and that definitely appears to be a transition..
Off-boost knock is going to be somewhat unavoidable, just make sure its not due to the tuning when your logging, look for large jumps in timing or fueling. And not just in adjacent cells, but its likely load is jumping from 80% to 120% as boost kicks in, thats a huge jump, and if its a huge jump in a very short time, the timing may also jump a few degrees, and that is a very very common source of knock.
Off-boost knock is going to be somewhat unavoidable, just make sure its not due to the tuning when your logging, look for large jumps in timing or fueling. And not just in adjacent cells, but its likely load is jumping from 80% to 120% as boost kicks in, thats a huge jump, and if its a huge jump in a very short time, the timing may also jump a few degrees, and that is a very very common source of knock.
Oct 13, 2006, 07:28 AM
#40
I couldnt open the office files for some reason but from the logs yesterday it is clearly likely noise. If it was nock occurring at partial throttle at 22+ counts while timing is pulled -10* and counts remain at 22 then I would say that it aint knock.
Go find the culprit (What is the clearance between DP and bar?)
Let us know
Anyone know why I can't open office word files that were easily opened yesterday
Go find the culprit (What is the clearance between DP and bar?)
Let us know
Anyone know why I can't open office word files that were easily opened yesterday
Last edited by C6C6CH3vo; Oct 13, 2006 at 07:32 AM.
Oct 13, 2006, 09:17 AM
#41
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Originally Posted by C6C6CH3vo
I couldnt open the office files for some reason but from the logs yesterday it is clearly likely noise. If it was nock occurring at partial throttle at 22+ counts while timing is pulled -10* and counts remain at 22 then I would say that it aint knock.
Go find the culprit (What is the clearance between DP and bar?)
Let us know
Anyone know why I can't open office word files that were easily opened yesterday
Go find the culprit (What is the clearance between DP and bar?)
Let us know
Anyone know why I can't open office word files that were easily opened yesterday
If I understand your logic correctly - you're saying since the knock count was so high and the timing got retarded some -10* - the knock should have at least gone down because of the retard.
Makes sense
I'm going to be changing my oil the weekend so while I'm under there I'll take a look at the clearance.
Oct 13, 2006, 10:00 AM
#44
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Originally Posted by joeymia
just out of curiosty do you have tubular headers? I had megan headers on my car which cracked and I was having all types of random knock. I removed the headers and it went away.
The only mods are in my sig.